clean-architecture-backend-template/CLAUDE.md

CLAUDE.md

Repository guidance for the Java 21 + Spring Boot 4.0.8 Clean Architecture template.

Prime Directive

Preserve architecture before optimizing for speed. The following eight HARD-STOP conditions are a synchronized summary of the canonical local policy in AGENTS.md:

1. domain-core gains framework, transport, database, or cloud dependencies.
2. A controller directly uses a repository, Spring Data interface, or persistence entity.
3. An inbound DTO leaks into application-core or domain-core.
4. Business rules move into mappers, filters, configuration, settings, or controllers.
5. Project dependencies violate src/config/architecture/modules.json or the Gradle dependency gate.
6. Completion is claimed without the relevant verification or a named reason it could not run.
7. A repository/corpus conclusion is made without evidence proportional to its scope and risk.
8. Non-trivial work closes without the required LLM Wiki capture or a reported capture block.

If this summary drifts from AGENTS.md, AGENTS.md wins and this summary must be resynchronized.

Gradle policy authorities

• src/config/architecture/modules.json: every registered leaf identity, repository-relative source paths, Gradle paths, allowed production project dependency edges, and the exact runtime memberships of both composition roots. The registry owns the leaf list and its size; no document restates the count, because a number written in prose drifts the moment a leaf is added.
• src/settings.gradle: fail-closed registry validation, project inclusion, and directory mapping.
• src/build.gradle: verifyCleanArchitectureDependencies and the other architecture-wide verification tasks.

Commit policy is human-only: agents do not stage, commit, amend, or push implementation changes.

Proportional workflow

• Low risk: work in the owning leaf, follow its nearest guidance, and run the focused check.
• Medium risk: use the relevant Superpowers design, planning, TDD, debugging, and review workflows in proportion to the affected boundaries.
• High risk: make architecture and behavior decisions explicit, use staged architecture/spec/quality review, and run architecture-wide verification authorized by the task.

Risk comes from change surface and runtime, security, data, or public-contract impact, not file count.

Module families

src/config/architecture/modules.json owns the complete leaf list. Root guidance summarizes families; the nearest src/**/CLAUDE.md owns local rules. verifyDocumentedLeafCount fails the build when a policy document states a leaf count that the registry does not agree with.

Family	Responsibility	Stable dependency direction
domain-core	Pure domain model, invariants, events, ports	Java stdlib and registered value-only contracts
application-core	Commands, use cases, application policies, transaction ports	domain-core, shared-contract
adapter:inbound:*	HTTP, gRPC, GraphQL, WebSocket transport boundaries	application/domain/shared contracts
adapter:outbound:persistence-*	JPA/PostgreSQL and MongoDB persistence adapters	application/domain/shared contracts as registered
adapter:outbound:*	support, messaging, cache, notification, storage, file, HTTP client, identifier capabilities	application/domain/shared and registered support edge
shared-contract	Skeleton-wide operational contracts	Java stdlib only
messaging:*	Vendored messaging platform: a product with its own API, SPI, adapters and composition boundary, not a layer of this application	messaging:* only — it depends on no domain-core, application-core, or shared-contract type
sample-portfolio	Fixture/reference consumer	registered runtime leaves; never a production dependency
app-bootstrap	Spring Boot entrypoint and composition root	registered runtime leaves

The messaging:* family is the one entry that is not a Clean Architecture layer, and it is listed so that the exception is stated rather than inferred from a directory. It is a vendored library — its own *-api leaves are its ports, its broker leaves are its adapters, its starter is its composition root — and the messaging module review (docs/reviews/2026-08-14-messaging-module-code-review.md MSG-023 §6.2) chose that layout deliberately over folding it into adapter:outbound:*. This application is supposed to reach it the way it reaches any library: through an application-owned port satisfied by an anti-corruption bridge in adapter:outbound:messaging. That bridge does not exist yet (MSG-015), so today the composition root wires the starter directly; src/messaging/CLAUDE.md holds the detail.

Never infer an individual leaf's Gradle path, allowed dependency, or test command from this table. Read its gradle_path, allowed_dependencies, and runtime_memberships from src/config/architecture/modules.json; derive the focused test from that Gradle path.

Layer workflow

For a full use case, work in this order:

domain-core
  -> application-core
  -> adapter:outbound:* (or persistence/identifier)
  -> adapter:inbound:*
  -> app-bootstrap wiring

Layer-only work stays inside that registered leaf plus its tests. If a required fix crosses a layer or writable scope, stop and request context rather than expanding silently.

Testing

• domain-core: pure JUnit unit tests.
• application-core: use-case tests with hand-rolled fakes; no web or persistence context.
• inbound adapters: focused transport slice/contract tests.
• persistence adapters: mapping/port contract tests; use a real datastore only when vendor semantics require it.
• other outbound adapters: port contract tests with fake external systems; no real network.
• identifier: pure deterministic unit tests.
• bootstrap/settings: binding, validation, wiring, and architecture tests.

From src/, read the owning leaf's gradle_path from config/architecture/modules.json and run ./gradlew <gradle-path>:test --console=plain. Architecture-wide commands:

./gradlew verifyCleanArchitectureDependencies --console=plain
./gradlew :app-bootstrap:test --tests 'dev.caskeleton.bootstrap.architecture.*' --console=plain
./gradlew verifyPublicPathSnapshot --console=plain
./gradlew verifyEnvKeys --console=plain

Use public-path and env-key checks only when their surfaces changed. Full test or check requires the controller's workflow authorization.

Advisory and reporting

Use dependency-DAG/topological reasoning and 3–5 materially distinct alternatives when that many exist; use fewer when the option set is smaller. Judgment findings include falsifiable assumptions and counterarguments. Deterministic compile, dependency, secret, or failed-test findings use Rule → Evidence → Fix without manufactured debate.

Citation verification is profile-based: none for review-lite, blocking citations for review-standard, and all material citations for audit-deep/regulated. Durable reports are triggered by high risk, at least 3 blocking findings, an architecture decision, explicit user request, or the regulated profile. Otherwise a concise result is allowed.

LLM Wiki capture

For non-trivial implementation or workflow changes, use the exact vault path and capture sequence in AGENTS.md. If the controller explicitly excludes wiki writes for a dispatched task, report the handoff instead of writing outside scope.